The present invention relates generally to optical network systems, and more particularly, a system and method for providing a control architecture in an optical burst-switched network.
Data traffic over networks, particularly the internet, has increased dramatically over the past several years, and this trend will continue with increasing number of users and the introduction of new services which require more bandwidth. The enlarged volume of internet traffic requires a network with high capacity routers capable of routing data packets with variable lengths. One option is the use of optical networks. However, current optical networks use only a small fraction of the bandwidth available on a single optical fiber.
The emergence of dense-wavelength division multiplexing (DWDM) technology has helped to overcome the bandwidth problem encountered by current optical networks. A single DWDM optical fiber has the capability of carrying as much as ten terabits of data per second. However, this creates a serious mismatch with current switching technologies which are capable of switching data at rates of up to a few gigabits per second. While emerging ATM switches and IP routers can be used to switch data using the individual channels within a DWDM fiber, typically at 2.4 gigabits per second or ten gigabits per second, this approach implies that tens or hundreds of switch interfaces must be used to terminate a single DWDM fiber with a large number of channels. This could lead to a significant loss of statistical multiplexing efficiency when the parallel channels are used simply as a collection of independent links, rather than as a shared resource.
Different approaches advocating the use of optical technology in place of electronics in switching systems have been proposed, however the limitations of optical component technology has largely limited optical switching to facility management applications. One approach, called optical burst-switched networking, attempts to make the best use of optical and electronic switching technologies. The electronics provides dynamic control of system resources by assigning individual user data bursts to channels of a DWDM fiber, while optical technology is used to switch the user data channels entirely in the optical domain.
Previous optical burst-switched networks designed to directly handle end-to-end user data channels have been disappointing and have shown the limitations of current optical components. For example, one prior art optical burst-switched network utilized ATM switches in the control network which made the design of the control network much more complicated and less efficient. Other prior art optical burst-switched networks used electronic buffers in the optical routers, thus the optical burst-switched network was not purely optical. The electronic buffers did not provide end-to-end transparent optical paths for data bursts. Thus, little has been done to stimulate any serious move toward optical burst-switching networks.
The present invention provides a packet switching system and method that substantially eliminates or reduces disadvantages and problems associated with previously developed packet switching systems and methods used for switching data packets across a network.
More specifically, the present invention provides an optical burst-switching control architecture for. switching data packets entirely in the optical domain. The control architecture for an optical burst-switched network includes an electronic ingress edge router, a switch control unit at each hop, and an electronic egress edge router. The electronic ingress edge router assembles multiple data packets into a burst. The switch control units at each hop configure the optical switching matrix to switch the burst through the optical burst-switched network. Finally, the electronic egress edge router receives the burst from the optical burst-switched network and disassembles the burst into multiple data packets.
The present invention provides an important technical advantage by providing a purely optical network, thus providing end-to-end optical paths for data bursts.
The present invention provides another technical advantage by using conventional IP routers rather than ATM switches, thus simplifying the design of the pure optical network""s control architecture.
The present invention provides another important technical advantage by providing an optical network with increased bandwidth per optical fiber, thus lowering the cost and increasing demand for bandwidth.
The present invention provides another technical advantage by providing an edge router and burst assembly mechanism which assembles data packets into bursts and forwards them to the core optical network according to an optical burst-switching protocol, thus circumventing potential bottlenecks of electronic processing.